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From aaron morton <aa...@thelastpickle.com>
Subject Re: HOW TO select a column or all columns that start with X
Date Wed, 03 Aug 2011 12:03:38 GMT
and AsciiType


-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com

On 3 Aug 2011, at 16:35, eldad87 wrote:

> Thank you!
> Will this situation work only for UTF8Type comparator?
> 
> 
> On Wed, Aug 3, 2011 at 4:50 AM, Tyler Hobbs <tyler@datastax.com> wrote:
> A minor correction:
> 
> To get all columns starting with "ABC_", you would set column_start="ABC_" and column_finish="ABC`"
(the '`' character comes after '_'), and ignore the last column in your results if it happened
to be "ABC`".
> 
> column_finish, or the "slice end" in other clients, is inclusive.  You could of course
use "ABC_~" as column_finish and avoid the check if you know that you don't have column names
like "ABC_~FOO" that you want to include.
> 
> 
> On Tue, Aug 2, 2011 at 7:17 PM, aaron morton <aaron@thelastpickle.com> wrote:
> Yup, thats a pretty common pattern. How exactly depends on the client you are using.

> 
> Say you were using pycassam, you would do a get() http://pycassa.github.com/pycassa/api/pycassa/columnfamily.html#pycassa.columnfamily.ColumnFamily.get
> 
> with column_start="ABC_" , count to whatever, and column_finish not provided. 
> 
> You can also provide a finish and use the highest encoded character, e.g. ascii 126 is
~ so if you used column_finish = "ABC_~" you would get everything that starts with ABC_
> 
> Cheers
> 
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> @aaronmorton
> http://www.thelastpickle.com
> 
> On 3 Aug 2011, at 09:28, Eldad Yamin wrote:
> 
>> Hello,
>> I wonder if I can select a column or all columns that start with X.
>> E.g I have columns ABC_1, ABC_2, ZZZ_1 and I want to select all columns that start
with ABC_ - is that possible?
>> 
>> 
>> 
>> Thanks!
> 
> 
> 
> 
> -- 
> Tyler Hobbs
> Software Engineer, DataStax
> Maintainer of the pycassa Cassandra Python client library
> 
> 


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